A method to modify an aircraft including: disconnecting a first engine control device from command cables and transmission cables, wherein the first engine control device is in a fuselage section forward of a pressure bulkhead; replacing the engine control device with a jumper connector positioned in the fuselage section, wherein the jumper connector electrically connects the command cables to the transmission cables; installing a second engine control device in the fuselage aft of the pressure bulkhead, wherein the second engine control device is in an engine compartment of the fuselage; connecting the second engine control device to transmission cables at a location at or near the pressure bulkhead; connecting sensor cabling directly to the second engine control device, and connecting the engine control device directly to the engine.

A gas turbine engine includes a first spool associated with a diffuser and a primary combustor and a second spool associated with a secondary combustor. The first spool includes a first compressor and a first turbine mounted to a first shaft, and the second spool includes a second compressor and a second turbine mounted to a second shaft. An inlet duct fluidly connects the diffuser to the second compressor. An outlet duct assembly fluidly connects the second turbine to the diffuser and the primary combustor.

An assembly for a gas turbine engine includes a casing centered on a longitudinal axis and including an upstream portion, a central portion and a downstream portion arranged successively along the longitudinal axis, an attachment system include plural tie rods, and an accessory gearbox arranged within a space delimited axially by the upstream portion and the downstream portion and radially by the central portion, the accessory gearbox being solely attached to the upstream portion or solely attached to the downstream portion by the attachment system.

A hybrid electric gas turbine engine system includes a first compressor and an auxiliary compressor. The first compressor is configured to output first compressed air. The auxiliary compressor is configured to operate in parallel with the first compressor to output second compressed air. A controller is configured to selectively activate the first compressor or the auxiliary compressor based on an operating condition of the hybrid electric gas turbine engine system.

An auxiliary power unit (APU) includes, in serial flow communication: an engine compressor, a combustor and a turbine, the turbine rotatable about an engine axis. A first shaft operatively connects the turbine to the engine compressor and extends non-parallel to the engine axis. A second shaft operatively connects the turbine to a load and extends non-parallel to the engine axis. A method of operating an APU is also described.

The electrical power generation system including a micro-turbine including a combustor, a first stage turbine configured to be driven by a combustor exhaust from the combustor, at least one compressor operably connected to the combustor to provide a compressed airflow to the combustor, a catalytic converter configured convert the combustor exhaust to a catalytic exhaust that includes at least exothermic heat, a second stage turbine configured to be driven by the catalytic exhaust from the catalytic converter, and one or more shafts connecting the first stage turbine and the second stage turbine to the at least one compressor such that rotation of the first stage turbine and the second stage turbine drives rotation of the at least one compressor.

A starter assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a fluid-actuated starter coupled to a spool, and a controller operable to cause a reduction in torque output of the starter in response to determining that a first threshold is met. The first threshold relates to an engine operational condition. A method for starting a gas turbine engine is also disclosed.

Gas turbine engines are described. The gas turbine engines include a compressor section, a combustor section, a turbine section, and a nozzle, wherein the compressor section, the combustor section, the turbine section, and the nozzle define a core flow path that expels through the nozzle. A waste heat recovery system is operably connected to the gas turbine engine, the waste heat recovery system having a working fluid. An auxiliary cooling system is configured to provide cooling to a working fluid of the waste heat recovery system.

A radial turbine rotor associated with an engine includes a disk, and a plurality of blades spaced apart about a perimeter of the disk. Each blade includes a forward end, an aft end and a root. The radial turbine rotor includes a plurality of sectors, with each sector coupled to the root of a respective blade of the plurality of blades. Each sector of the plurality of sectors defines a first surface configured to contact a working fluid and a second surface configured to be coupled to the disk, and each sector of the plurality of sectors defines at least one pocket between the first surface and the second surface proximate the forward end that extends toward the aft end. The radial turbine rotor includes a feather seal slot defined between adjacent sectors of the plurality of sectors proximate the first surface.

An auxiliary power unit for an aircraft, having a compressor, an intercooler including first conduit(s) having an inlet in fluid communication with the compressor outlet and second conduit(s) configured for circulation of a coolant therethrough, an engine core having an inlet in fluid communication with an outlet of the first conduit(s), and a bleed conduit in fluid communication with the outlet of the first conduit(s) through a bleed air valve. The auxiliary power unit may include a generator in driving engagement with the shaft of the engine core to provide electrical power for the aircraft. A method of providing compressed air and electrical power to an aircraft is also discussed.